1. Field of the Invention
This invention relates to eyeglasses and spectacles, and more particularly to eyeglasses with movable auxiliary glasses.
2. Description of the Prior Art
Many special types of eyeglasses are available to the public including a wire frame known as aviator glasses. However, uses of aviator glasses by the aviator and golfer have particular needs which have not yet been satisfied by those aviation style eyeglasses presently available.
The aviator needs to focus clearly at three distances: he must be able to read his maps (close vision); he must see his instruments clearly (intermediate vision); and he must be able to look out his windscreen (distance vision). Trifocal glasses do not give adequate vision range. Presently, most aviators who need corrective lenses must therefore change glasses during flight to achieve clear vision at a variety of distances. Besides the inconvenience of changing glasses, there is the hazzard of distraction and the possibility of breaking the glasses not being worn.
A golfer also needs to see clearly at several distances. Here again, trifocals are not the answer for many people. Most golfers do not wish to be encumbered with an extra set of glasses while on the golf course.
There are auxiliary eyeglasses available, but only for plastic-framed glasses. These glasses are fastened to an original pair of eyeglasses at the screws which hold the temple pieces to the lens frame by a ball and socket arrangement. This method is not adaptable to wire-framed, aviator style glasses because of the curvature of the wire frames. Also, in prior art plastic frames, there is a large space between the tops of the two sets of eyeglasses, yet the bottom of the auxiliary lenses touch the original glasses, sometimes scratching these.
Presently available are some flip-up auxiliary eyeglasses used as sunglasses. These eyeglasses too easily slip back over the original prescription eyeglasses. There is a need for a means of keeping the auxiliary lenses in the upper position, especially when both eyeglasses have corrective lenses, or vision may be impaired.
There is, therefore, a great need for wire frame glasses for aviators and the like which will have more than one pair of eyeglasses on one combined frame. Aviators have a need for eyeglasses which will be easy to manipulate to provide clear, wide ranging vision at varying distances. Most importantly, they must be especially sure that the lenses remain in the desired position. No device is presently known which simultaneously offers, on a pair of wire-framed eyeglasses, dual eyeglasses together with a means for holding the auxiliary eyeglasses firmly when the lenses are in the upper position.